1. Field of the Invention
The present invention relates to a temperature switch or performing on/off operation according to a temperature change, in particular, to a temperature switch with a bimetal disc which inversely deforms between a concave shape and a convex shape according to a temperature change.
2. Description of the Prior Art
As a prior art reference, a temperature switch 1 with the construction shown in FIG. 4 has been used. The temperature switch 1 has a shoulder portion 3 on the outer periphery of a lower portion of a casing 2. On the shoulder portion 3, a bimetal disc 4 is disposed. A center portion of the disc 4 is connected to a switch portion 5 with a rod 6.
Conventionally, this temperature switch 1 is used in such a manner that the outer surface of a bottom portion of the casing 2 is in contact with a test subject in a plane shape. When the temperature of the test subject 7 changes, the temperature change is transferred to the disc 4 through the casing 2. Thus, the disc 4 was deformed from a concave shape to a convex shape. The disc 4 which was deformed in the convex shape causes the rod 6 to upwardly move and the switch portion 5 to operate.
This type of temperature switch is used for applications such as an alarm apparatus or a temperature control apparatus. Thus, when an abrupt temperature change takes place in a test subject, it should be detected as soon as possible without a delay.